For many years spine fin tubing has been used in heat exchange structures for air conditioners. In such heat exchangers the spine fin ribbon is wrapped about the evaporator tubing in a very compact fashion; that is, the spine fin ribbon is wound so that adjacent passes of ribbon are in contact and the fingers or spines are very closely spaced. With such a construction the spines or fingers provide a very large total surface area for heat transfer.
Despite the successful use of spine fin tubing in air conditioners for many years, such heat exchange structures were not used in refrigerator evaporators. It has been the belief of many experienced practitioners that spine fin materials are not suitable for use in refrigerator evaporators. One basis for the belief was that the frost build up in a refrigerator evaporator quickly would render the spine fin ineffective as a heat transfer structure. In addition, it was believed that spine fin structures, as used in air conditioners, were too delicate to withstand the handling involved in manufacturing and installing refrigerator evaporators. On the other hand it was believed that, if the size of the spines were increased sufficiently to withstand the rigors of manufacturing, then the evaporator would not have sufficient heat exchange capacity to be effective with the stringent size limitations normally imposed upon such evaporators.
Co-pending U.S. Pat. No. 5,067,322 of David G. Beers issued Nov. 26, 1991 and assigned to General Electric Company, assignee of the present application, discloses a refrigerator evaporator incorporating a ribbon of spine fin material wound about the outer periphery of the evaporator tubing with a series of fingers extending perpendicularly outward of the tube along each edge of the ribbon, and is incorporated herein by reference.
However, it is desirable to further optimize the heat transfer between the spine fin material and the air passing over the evaporator.
Accordingly, it is an object of this invention to provide an improved refrigerator with an evaporator incorporating a spine fin heat exchange structure of improved heat transfer capability.
It is another object of the present invention to provide an improved structure in which the distal end portions of the spine fin fingers extend perpendicularly of the direction of air flow across the elongated evaporator tubing.
It is still another object of this invention to provide such an improved structure in which a spine fin ribbon has a base wrapped about the evaporator tubing in an open spiral with fingers extending outwardly of said evaporator tubing along each edge of the base and with the distal ends of the fingers bent to extend generally perpendicular to the root portions of the fins.
It is yet another object of this invention to provide such an improved structure in which the finger distal ends all extend in the same direction.
It is yet another object of this invention to provide such an improved structure in which the finger distal ends overlie the corresponding portions of the spine fin base.
It is still another object of this invention to provide such an improved structure in which the finger distal ends extend axially of the tubing away from the corresponding portion of the spine fin base.
Further objects and advantages of the present invention will be apparent from the following description and features of novelty which characterize the invention will be pointed out in the claims attached to and forming a part of this specification.